Striker Hume underwent surgery after a challenge by Chris Morgan and is in a "stable condition" in a high dependency unit in hospital.
"The club may be seeking legal advice on the matter," Tykes manager Simon Davey told BBC Radio Sheffield.
"We've ended up with a life-threatening injury and a player in a hospital bed."
Former Leicester forward Hume, 25, was hurt in a clash with Sheffield United skipper Morgan as both challenged for a header in the first half.
His condition deteriorated on Sunday and he was taken in for surgery.
Morgan, who started his career at Barnsley, was booked over the incident by referee Andy D'Urso, but Davey was furious at the outcome.
"The decision not to show a red card was an absolute disgrace," he told the club website.
"Iain is now in hospital with a fractured skull because of that challenge that seemingly warranted only a yellow card."
Davey claimed both he and assistant manager Ryan Kidd had raised concerns over Hume's treatment by the Blades with ref D'Urso at half-time.
He added: "There is no timescale regarding when he will be fit enough to return, but he is in a stable condition."
The Blades responded to the news of Hume's injury in a club statement.
"Sheffield United are saddened and concerned to hear that Barnsley striker Iain Hume is being monitored in a high dependency unit following last Saturday's fixture," it read.
"We wish him a speedy and full recovery."
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I was always very proud of how Taylor and Boothroyd's Watford sides played a physical and aggressive style of football but always seemed to keep on the right side of the law and we don't want the game to become non-contact.
But when we praise people like Morgan as solid, no-nonsense and dependable for kicking the $h!t out of Carlos Tevez we can't be suprised that we end up with the prospect of legal proceedings.
Recently Stockport said they were considering legal action over a challenge by Colchester's Paul Reid.
Morgan, like Darren Purse is an absolute sub-human and also a total coward.
He has an obvious physical advantage over small players like Hume and Tevez but I don't see why he can't use that legally - I wonder if he challenges Henderson like that in training
Perhaps we shouldn't be suprised that this challenge also comes from a player who has been managed by Warnock and Blackwell ?